Synthesis of 8‐Desoxythunberginol A and (±)‐8‐Desoxy‐3,4‐Dihydrothunberginol A

A two step synthesis of title isocoumarin isolated from Homalium longifolium and its conversion into corresponding 3,4‐dihydroisocoumarin has been described. 3,4‐Dimethoxybenzoyl chloride on condensation with homophthalic acid afforded 3‐(3′,4′‐dimethoxyphenyl)isocoumarin which was demethylated to furnish the 8‐desoxythunberginol A, whereas its sequential saponification, reduction and demethylation yielded the (±)‐8‐desoxy‐3,4‐dihydrothunberginol A. The synthesized compounds were examined in vitro for antibacterial activity.     

A meso–meso β‐β β‐β Triply Linked Subporphyrin Dimer

A meso–meso β‐β β‐β triply linked subporphyrin dimer 6 was synthesized by stepwise reductive elimination of β‐to‐β doubly Pt^II‐bridged subporphyrin dimer 9 . Dimer 6 was characterized by spectroscopic and electrochemical measurements, theoretical calculations, and picosecond time‐resolved transient absorption spectroscopy. X‐ray diffraction analysis reveals that 6 has a bowl‐shaped structure with a positive Gaussian curvature. Despite the curved structure, 6 exhibits a remarkably red‐shifted absorption band at 942 nm and a small electrochemical HOMO–LUMO gap (1.35 eV), indicating an effectively conjugated π‐electronic network.     

Preparation of 8‐Aza‐7‐deazaaristeromycin and ‐neplanocin A and Their 5′‐Homologs

The synthesis of new members of the aristeromycin and neplaoncin A families of carbocyclic nucleosides possessing the 1H‐pyrazolo[3,4‐d]pyrimidine ring is reported. For this purpose, an adapted route to 4‐amino‐1H‐pyrazolo[3,4‐d]pyrimidine is described.     

A Concise Total Synthesis of (+)‐Tetrabenazine and (+)‐α‐Dihydrotetrabenazine

Highly concise asymmetric total syntheses of (+)‐tetrabenazine ( 1 ), a drug for the treatment of chorea associated with Huntington’s disease, and of (+)‐α‐dihydrotetrabenazine ( 2 ), an active metabolite of 1 , have been accomplished. Our synthetic route features a trans‐selective enol etherification, followed by an unprecedented cation‐dependent aza‐Claisen rearrangement to establish the carbon framework and two stereogenic centers of tetrabenazine. The syntheses consist of seven steps (34 % overall yield) for (+)‐ 2 and eight steps (22 % overall yield) for (+)‐ 1 .     

A Concise Total Synthesis of (−)‐Himalensine A

The daphniphyllum alkaloids are a structurally fascinating and remarkably diverse family of natural products. General strategies for the chemical synthesis of their challenging architectures are highly desirable for efficiently accessing these intriguing alkaloids and addressing their pharmaceutical potential. Herein, a concise strategy designed to provide general and diversifiable access to various daphniphyllum alkaloids is described and utilized in the asymmetric synthesis of (?)‐himalensine A, which was accomplished in 14 steps. Key features of this strategy include a Cu‐catalyzed nitrile hydration, a Heck reaction to construct the challenging 2‐azabicyclo[3.3.1]nonane motif, a Meinwald rearrangement reaction, six, pot‐economic reactions, and the minimal use of protecting groups, which significantly improved the overall synthetic efficiency.     

A Novel Synthesis of γ,δ‐Unsaturated Aldehydes from α‐Formyl‐γ‐lactones

A preparatively useful one‐step transformation of γ,γ‐disubstituted α‐formyl‐γ‐lactones into trisubstituted γ,δ‐unsaturated aldehydes is described, by means of catalytic amounts of either AcOH or AcOEt in the vapor phase over a glass support. A mechanistic rationale is proposed.     

A Convenient Synthesis of Functionalized α‐Methylidenebutano‐4‐lactams

A concise synthetic approach to functionalized α‐methylidenebutanolactams has been developed. The synthetic strategy is based on the preliminary assembly of the lactam template equipped with appropriate functionalities. Subsequent installation of the methylidene by a metalation/alkylation/elimination sequence completed the elaboration of the racemic title compounds.     

A practical synthesis of 5‐(4′‐methylbiphenyl‐2‐yl)‐1H‐tetrazole

Practical synthesis of 5‐(4′‐methylbiphenyl‐2‐yl)‐1H‐tetrazole, key intermediate in several angiotensin II receptor antagonists from 2‐fluorobenzonitrile in excellent yields and very high purity is described.     

A Photochromic Agonist for μ‐Opioid Receptors

Opioid receptors (ORs) are widely distributed in the brain, the spinal cord, and the digestive tract and play an important role in nociception. All known ORs are G‐protein‐coupled receptors (GPCRs) of family A. Another well‐known member of this family, rhodopsin, is activated by light through the cis/trans isomerization of a covalently bound chromophore, retinal. We now show how an OR can be combined with a synthetic azobenzene photoswitch to gain light sensitivity. Our work extends the reach of photopharmacology and outlines a general strategy for converting Family A GPCRs, which account for the majority of drug targets, into photoreceptors.