Di-tert-butylmethylsilyl (DTBMS) trifluoromethanesulfonate. Preparation and synthetic applications of DTBMS esters and enol ethers
✍ Scribed by Rajeev S. Bhide; Bruce S. Levison; Ram B. Sharma; Subrata Ghosh; Robert G. Salomon
- Book ID
- 104218183
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- French
- Weight
- 237 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
DTBMS tri fl ate, readil y avail able from d ichlor omethylsilane, provid es carboxyl i c esters whi ch resist r eduction by hydridoaluminate or a cid ca t a lyzed hydrolysi s, and vinylogous esters ( enol ethers of hydroxymethylene ke t ones) which resist 1, 4-addition of methyllithium.
A pr oc livi t y t oward 1, 4-addition of methyllithium t o th e trimethylsilyl (TMS) e ther 3a interfered with the 1,Z-additi on which we required f or pr ep a ri ng unsaturated a l de hyde 2 f ro m ahydroxym ethylene ketone 1. 1 The pr oblem was solved by blo cking 1,4-addition with bulky substituents on silicon. Thus , the proportion of 1,Z-adduct 4 versus 1,4-addllct 5 improved slightly with the t-buty1dimethylsilyl (TBDMS ) ether 3b and dramaticall y with the di-t-but ylmethyl s il yl (DTBMS) ether 3c (table 1). The aldehyde 2 was obtai ned i n 90% yield overall f rom 1 by silyla-