Consequences of acid catalysis in concurrent ring opening and halogenation of spiroketals

Organic Letters

Volumn 1, Issue 11, 1999, Pages 1815-1818

  LaCour, Thomas G ^a   Tong, Zhiwei ^a   Fuchs, Philip L ^a  

^a PURDUE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ACID; HALOGEN; SPIRO COMPOUND; STEROID;

ARTICLE; CATALYSIS; CHEMISTRY; SYNTHESIS;

ACIDS; CATALYSIS; HALOGENS; SPIRO COMPOUNDS; STEROIDS;

EID: 0033518065     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol991078r     Document Type: Article

References (25)

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13. 3, pyr·HCl) permitted complete reaction at 180°C (refs a-c and references therein).
14. 3; unit cell parameters a 13.4662 (18), b 12.613 (3), and c 14.726 (2) Å, β 105.497 (13)°, space group P21. Halides 2/10 prepared in this work were identical by NMR and TLC to that in ref 1 except for chloride content.
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16. 27]). and none showed minor peaks as in 5. 2a from entry 8. Table 1, appears to be >98% diastereomerically pure as judged by conversion to 3 and comparison to 3 prepared in ref 1.
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23. Rapid heating (immersion into a preheated bath as in ref 1 and Table 1) gave maximal iodide production. Slow heating (25 min to achieve 90 °C) of an identical mixture gave a 90% yield of 10a/b (4:1 ).
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