ChemInform Abstract: SYNTHESE UND EIGENSCHAFTEN VON 4‐CARBOAETHOXY‐2H‐FURANONEN‐(3)

Abstract

Die Ketoester (I) lassen sich mit den Chloracylchloriden (II) (analog auch mit entsprechenden α‐Acetoxy‐acylchloriden) in Gegenwart "von Mg‐äthylat in Benzol bei 10°C zu den Äthoxycarbonyldihydrofuranonen (III) umsetzen.

Total Syntheses of the Gregatins A–D and Aspertetronin A: Structure Revisions of These Compounds and of Aspertetronin B, Together with Plausible Structure Revisions of Gregatin E, Cyclogregatin, Graminin A, the Penicilliols A and B, and the Huaspenones A and B

“…Ideally, it would be suitable to provide not only (+)‐gregatin B [(+)‐( R )‐ 1c ] but also the third‐generation structures 2c – 10c of the other members of the gregatin/aspertetronin family. A whole array of existing 3(2 H )‐furanone approaches40–47 held little promise for such a strategy. In contrast, the γ‐acyloxy‐β‐oxo ester 43 had been reported to give type‐ c furanone 40 upon exposure to basic methanol (Scheme ) 48.…”

A new and facile synthesis of trialkylketenimines

“…1.15(6 H, d, 6.5 Hz, Me2), 3.47 (1 H, septet, 6.5 Hz, CH) (100), 56 (8), 55 (10), 43 (20), 42 (24) , 41 (24), 40 (8), 39 (9) 139 (M+, 27), 124 (8), 83 (57), 68…”

“…(78), 57 (100), 56 (10), 55 (21), 54 (7), 41 (51), 39 (14) 139 (M+, 36), 124 (3), 97 (65), 96 (9), 82 (100), 70 (10), 69 (6), 68 (6), 55 (32), 54 (7), 43 (30), 42 (12), 41 (38), 39 (14) 153 (M+, 28), 138 (8), 97 (78), 82…”