Electronic spectra of 12-S-CIS conformationally locked retinals

The electronic absorption spectra of the four new 12-$\text{s}$-$\text{cis}$-locked retinals (1a–1d) bearing 7-$\text{trans}$, 11-$\text{trans}$ double bond geometries are described and compared with those of analogous 7-$\text{trans}$, 11-$\text{cis}$-geometries (1e–1h) and parent retinals (2a-h).     

A stereoselective 3-endo-alkyl-5,6-dehydroisoquinuclidine synthesis.

Cycloaddition of N-carbethoxy-2-alkyl-1,2-dihydropyridines $\text{4}$ with phenylvinylsulfone $\text{5}$ provides adducts $\text{6}$, which upon desulfonylation afford stereoselectively N-carbethoxy-3-$\text{endo}$- alkyl-5,6-dehydroisoquinuclidines $\text{1}$.     

Stereoselective synthesis of the optically active functionalized 1,3,5-all-anti-triol

The optically active 1,3,5-$\text{all}$-$\text{anti}$-triol $\text{20}$ was synthesized starting from ($\text{S}$)-(-)-malic acid with complete stereoselection, based on the stereoselective reduction of cyclic β-keto acetal and successive transthioacetalization.     

13C-NMR spectra of 6-aminohexyl glycosides of O-β-D-galactopyranosyl-2-acetamido-2-deoxy-β-D-glucopyranose

¹³C-NMR spectral data on 6-aminohexyl glycosides of $\text{O}$-β-$\text{D}$-galactopyranosyl-2-acetamido-2-deoxy-β-$\text{D}$-glucopyranose are pr     

Synthesis of β-d-mannopyranosides and regioselective o-alkylation of dibutylstannylene complexes

Alkylation of dibutylstannylene complexes of 3,4,6-tri-$\text{O}$-benzyl-$\text{D}$-mannopyranose, methyl 6-$\text{O}$-trityl-α-$\text{D}$-mannopyranoside and methyl α-$\text{D}$-mannopyranoside gives respectively β-$\text{D}$-mannopyranoside and 3-$\text{O}$-alkyl derivatives with high selectivity.     

Diastereoselective synthesis of N-acetyl-D,L-acosamine and N-benzoyl-D,L-ristosamine

N-Acyl derivatives of $\text{D}$,$\text{L}$-acosamine and $\text{D}$,$\text{L}$-ristosamine were synthesized with high stereo selectivity utilizing intramolecular Michael addition of γ- and δ-carbomoyloxy-α,β-unsaturated esters.     

Steroidal antifeedants from the dorid nudibranch Aldisasanguineacooperi

Two steroids, 3-oxo-chol-4-ene-24-oic acid ($\text{2}$) andi ts unsaturated analog $\text{4}$ have been isolated from the dorid nudibranch $\text{Aldisa}$$\text{sanguinea}$$\text{cooperi}$, and the acid $\text{2}$ has been shown to have antifeedant properties.     

Synthesis of both 2,3-erythro- and 2,3-threo- isomers of aplidiasphingosine,a bioactive marine terpenoid

2,3-$\text{threo}$- and 13,14-$\text{erythro}$-Relative configurations were proposed for aplidiasphingosine by synthesizing both its 2,3-erythro- and 2,3-$\text{threo}$- isomers and examining their ¹³c-NMR spectra.