Stereocontrolled synthesis of a C(1)-C(15) segment for the marine macrolides swinholide A and scytophycin C: use of a vinylogous Mukaiyama aldol reaction
摘要:
The C1-C-15 segment (+/-)-8 of swinholide A/scytophycin C was prepared in eight steps from (E)-4-chlorobut-3-en-2-one (10) in 19% overall yield with 87% diastereoselectivity. The C-7 stereocenter was controlled by the novel, vinylogous Mukaiyama aldol reaction, 16 + 18 --> 19, mediated by BF3.OEt2. The related C1-C-13 segment (+/-)-9 for misakinolide A was also prepared.
The total synthesis of swinholide A. Part 2: A stereocontrolled synthesis of a c1–c15 segment
作者:Ian Paterson、Julian D. Smith、Richard A. Ward
DOI:10.1016/0040-4020(95)00547-l
日期:1995.8
The C1–C15 segment 3 of swinholide A was prepared in 10 steps (14% yield) from the methyl ketone 13. Key steps include (i) the asymmetric aldol reaction. 13 → 35, followed by cyclisation to give the dihydropyrone 36, (ii) the Ferrier-type rearrangement, 38 → 39, and (iii) the vinylogous Mukaiyama aldol reaction, 39 → 40.