Abstract
Diels-Alder cyclizations of N-acyl imines derived from glyoxylates 5 and 8 stereoselectively produced cis-fused bicyclo-1,3-dihydrooxazine γ-lactones 7 and 10, respectively. The cycloaddition failed to yield the corresponding δ-lactone 12 derived from precursor 11. Selective ring cleavages of cycloadduct 2 afforded hydroxy amide 13 and α-amino lactone 14. Efficient application of this methodology to the stereoselective synthesis of the N-terminal amino acid portion 15 of nikkomycin B (16) is described. Diels-Alder precursor 21, readily available in three steps from known allylic chloride 17, was cyclized to the bicyclodihydrooxazine 22. This compound was readily converted to lactone 26.
Original language | English (US) |
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Pages (from-to) | 850-854 |
Number of pages | 5 |
Journal | Journal of Organic Chemistry |
Volume | 53 |
Issue number | 4 |
DOIs | |
State | Published - Feb 1 1988 |
All Science Journal Classification (ASJC) codes
- Organic Chemistry