Stereoselective total synthesis of (+)-myriocin from D-mannose

The stereoselective total synthesis of myriocin 1 from D-mannose is described; the carbon framework with three contiguous chiral centers including a tetra-substituted carbon with nitrogen was effectively constructed using Overman rearrangement as the key reaction.     

Stereoselective synthesis of (+)-boronolide

The delta-lactone boronolide (+)-1, a pharmacologically active, naturally occurring product, has been synthesized in enantiopure form with L-erythrulose as the chiral starting material. The key steps of the synthesis were a highly stereoselective aldol-reduction one-pot sequence, an indium-mediated diastereoselective aldehyde allylation, and a ring-closing metathesis.     

Stereoselective synthesis of (+)-spectaline

Our synthesis of (+)-spectaline revealed that the methodology involving diastereoselective palladium(0)-catalyzed oxazoline formation and intramolecular reductive amination by catalytic hydrogenation of an oxazoline is an effective method for the asymmetric synthesis of natural products possessing complex functionalized piperidine cores.     

Stereoselective synthesis of (+)-blastmycinone

(+)-Blastmycinone has been synthesized based on diastereoselective synthesis of (2R,3S)-2-hydroxy-3-(1-propenyl)heptanoic acid by the ester enolate Claisen rearrangement of (R)-(E)-1-methyl-2-heptenyl glycolate and stereoselective reduction of α-hydroxy ketone with Zn(BH₄)₂.     

Stereoselective synthesis of (+)-lauthisan

Stereoselective synthesis of (+)-lauthisan has been accomplished starting from d-glyceraldehyde acetonide by combination of diastereoselective alkylation and ring-closing metathesis. High degree of 1,3-asymmetric induction has been realized in ether system.     

Stereoselective synthesis of (+)-hyptolide

The first total synthesis of the naturally occurring lactone (+)-hyptolide is described. Ethyl l-lactate was the chiral starting material. Key steps of this 15-step synthesis were a Brown's asymmetric allylation, a Carreira's asymmetric ethynylation and a ring closing metathesis.     

Stereoselective synthesis of (+)-goniothalesdiol

Stereoselective synthesis of antitumor tetrahydrofuran (+)-goniothalesdiol was achieved in high overall yield from (-)-D-tartaric acid. Key features include an FeCl3 mediated THF formation with very high selectivity. Synthesis of natural gonithalesdiol and its analogue 2,5-bis-epi-goniothalesdiol was achieved from a common intermediate.     

Stereoselective synthesis of (+)-boronolide

An efficient enantio- and stereocontrolled total synthesis of (+)-boronolide from valeraldehyde is described. The key steps include a Sharpless asymmetric dihydroxylation, a chelation controlled Grignard reaction followed by Sharpless asymmetric epoxidation and a ring closing metathesis.     

Stereoselective synthesis (+)-cephalosporolide D

A simple and efficient stereoselective synthesis of macrolactone, (+)-cephalosporolide D has been accomplished in 13 steps from inexpensive and commercially available starting materials in an overall yield of 17%, respectively. This convergent synthesis utilizes Maruoka asymmetric allylation reaction, Grubb’s cross metathesis for the formation of a fully functionalized acid, and Yamaguchi lactonization as key steps.     

Stereoselective total synthesis of (+)-varitriol

Stereoselective total synthesis of (+)-varitriol, an antitumor natural product, was accomplished by two versatile strategies starting from the commercially available d-(−)-ribose and ethyl (S)-lactate. The key steps involved in the synthesis of the target molecule are epoxidation, cyclization, dihydroxylation and Diels-Alder reaction.     

Stereoselective total synthesis of (+)-artemisinin

The total synthesis of the novel antimalarial drug, a sesquiterpene endoperoxide, (+)-artemisinin is described. The approach is flexible and stereoselective. The use of an intermolecular radical reaction on an intermediate iodolactone and a Wittig reaction on a ketone were employed for the synthesis.     

Stereoselective synthesis of (+)-secosyrin 1

A Chiron approach for the synthesis of (+)-secosyrin 1 from d-mannitol has been described. The key steps are a stereoselective Wittig reaction and an intramolecular Michael addition on the disubstituted butenolide, leading to a highly stereoselective formation of the tertiary chiral centre of (+)-secosyrin 1.     

Stereoselective synthesis of (+)-IKD-8344

Total synthesis of IKD-8344 was accomplished via stepwise cyclodimerization of the monomeric seco acid under Yamaguchi conditions. In the synthesis of the monomeric seco acid, Wittig olefination reaction was employed for an efficient bond formation at C7-C8. The threo-trans oxolane unit for the rings a and c was prepared via intramolecular Williamson ether synthesis of the hydroxyl mesylate prepared via asymmetric aldol reaction. Radical cyclization of a β-alkoxymethacrylate intermediate furnished the threo-cis oxolane unit for the b ring fragment.     

Stereoselective total synthesis of (+)-cardiobutanolide

Stereoselective synthesis of styryllactone (+)-cardiobutanolide was accomplished in good overall yield from d-(-)-tartaric acid. Key features of the synthesis include the elaboration of a gamma-hydroxy butyramide obtained from the dimethylamide of tartaric acid, involving a combination of the addition of 1,3-dithian-2-yllithium and stereoselective reduction.     

Stereoselective synthesis of (+)-radicamine B

A simple and efficient stereoselective synthesis of naturally occurring pyrrolidine alkaloid, radicamine B has been accomplished in 13 steps from the commercially available starting materials with an overall yield of 9.75%. The synthesis utilizes Sharpless asymmetric epoxidation and Horner-Wadsworth-Emmons (HWE) olefination as key steps.     

Stereoselective total synthesis of (+)-aspicilin

A stereoselective synthesis of (+)-aspicilin is described. Regio- and stereoselective functionalization by intramolecular participation of the sulfinyl group, ene reaction, and macrolactonization by Wadsworth-Emmons reaction employing Masamune-Roush protocol are the key steps of the route.     

Stereoselective total synthesis of (+)-boronolide

A seteroselective total synthesis of (+)-boronolide is described. The key steps are Sharpless asymmetric dihydroxylation, Shibasaki's asymmetric Henry reaction, asymmetric allylation and ring closing metathesis.     

Stereoselective formal total synthesis of (+)-methynolide

A highly stereoselective and convergent formal total synthesis of (+)-methynolide is described. The salient features of this synthesis have been the construction of the C1-C7 and C8-C11fragments via a desymmetrization approach, Sharpless asymmetric epoxidation of an allyl alcohol, respectively, and linkage of both the fragments by Nozaki-Hiyama-Kishi reaction.