Ready access to [5,6,5]-Trioxa-spiro and fused ketals via ag-catalyzed cascade annulation of 4-pentyn-1-ols and aldehydes
| Title | Ready access to [5,6,5]-Trioxa-spiro and fused ketals via ag-catalyzed cascade annulation of 4-pentyn-1-ols and aldehydes |
| Publication Type | Journal Article |
| Year of Publication | 2024 |
| Authors | Vinodkumar, R, Nakate, AK, Gamidi, RKrishna, Kontham, R |
| Journal | Organic Letters |
| Volume | 26 |
| Issue | 34 |
| Pagination | 7116-7121 |
| Date Published | AUG |
| Type of Article | Article |
| ISSN | 1523-7060 |
| Abstract | In this study, we unveil the versatility of 4-pentyn-1-ols as carbonyl surrogates for the unprecedented synthesis of diverse oxygen heterocycles, including [5,6,5]-bis-spiroketals (trioxadispiroketals) and [5,6,5]-furano-spiroketals related to bioactive natural products. These reactions commence with the pi-activation-induced intramolecular hydroalkoxylation of 4-pentyn-1-ols, yielding cyclic enol ethers, which undergo subsequent three-component annulation with aldehydes in a [2+2+1+1] fashion, resulting in the formation of [5,6,5]-bis-spiroketals. Notably, the distinctive steric features of alkynyl alcohols, particularly those with a secondary or tertiary alcohol functionality, dictate divergent reaction pathways, leading to the formation of [5,6,5]-furano-spiroketals. |
| DOI | 10.1021/acs.orglett.4c02357 |
| Type of Journal (Indian or Foreign) | Foreign |
| Impact Factor (IF) | 5.2 |