A convergent approach for the total synthesis of the α-glucosidase inhibitor (−)-panaxjapyne-C

Stereoselective Total Syntheses of (R )-Strongylodiols A, B, C and D

“…Our attention was initially focused on the synthesis of the common key intermediate 9 , which can be used for the synthesis of all four‐target molecules. Thus, the synthesis began with an oxidation reaction of the readily available alcohol 10 (synthesized earlier in our group from the commercially available (‐)‐diethyl D‐tartrate following known procedures in 3‐step sequence with an overall yield of 81 %) with iodoxybenzoic acid (IBX) to get the aldehyde which was subjected to a Wittig reaction with 9‐(benzyl)oxy‐1‐nonyl‐(triphenyl)phosphonium iodide 15 (synthesized from 1,9‐nonanediol in 3‐step sequence as shown in scheme 2) in presence of n‐BuLi to afford the olefin 16 as Z isomer exclusively. Compound 16 when exposed to 5 mol% Pd(OH) 2 under hydrogen atmosphere underwent one pot debenzylation and olefin reduction to yield the corresponding saturated alcohol 9 in 95 % yield (Scheme ).…”

“…The biological properties include antibacterial, anticancer, antiviral, enzyme‐inhibitory, sedative and neuritogenic activities . Our own interest in this class of compounds in synthetic aspect has led to the accomplishment of the total syntheses of diacetylenic polyol natural products oploxyne A, B, panaxjapyne C, petrosiol A, D and E(Figure ) . Strongylodiols A−D, isolated from the Okinawan marine sponge of the genus Strongylophora are the fist examples of long‐chain acetylene alcohols which exists as an enantiomeric mixture with a different ratio (strongylodiol A (91:9), stronglylodiol B (97:3), strongylodiol C (84:16) and strongylodiol D (95:5) with the major compound having R configuration in all the four molecules.…”

Stereoselective total synthesis and structural revision of the diacetylenic diol natural products strongylodiols H and I

“…In continuation to our research interest on the synthesis of acetylenic compounds [ 19 – 21 ], recently we have accomplished the total synthesis of the diacetylenic polyol natural products petrosiols A, D, E ( 11 , 12 , 13 ) [ 22 – 23 ] and strongylodiols A–D ( 1 – 4 ) [ 24 ]. Herein we describe the total synthesis of strongylodiols H and I ( 9 and 10 ).…”