Abstract
The combination of 10-12 kbar pressure plus Lewis acidic zinc dichloride promotes highly regioselective and stereoselective Diels-Alder cycloaddition between 3-bromo-2-pyrone, prepared in a new way, and unactivated terminal alkene 4-(tert-butyldimethylsiloxy)-1-butene. The conjugate base of A-ring allylic phosphine oxide 20 adds chemospecifically to the C-8 keto group of some C-8,C-24-diketones to form directly metabolically resistant 24-oxo analogs of 1α,25-dihydroxyvitamin D3 (calcitriol). Several of these new hybrid analogs are as efficacious in vitro as calcitriol at inhibiting growth of murine keratinocytes even at physiologically relevant 10-100 nanomolar concentrations.
Original language | English (US) |
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Pages (from-to) | 3299-3314 |
Number of pages | 16 |
Journal | Journal of Organic Chemistry |
Volume | 62 |
Issue number | 10 |
DOIs | |
State | Published - 1997 |
Externally published | Yes |
ASJC Scopus subject areas
- Organic Chemistry