Quaternary centers are rapidly and selectively installed in a series of seven‐membered and bridged cyclic oxonitriles through conjugate addition of an alkoxide to chloroalkenenitriles, followed by a Claisen rearrangement. Using this strategy, the stereogenic information of the carbinol in secondary allylic alcohols is transferred to the newly generated quaternary center. Experimentally, the sequence rapidly gives alkyl cyanocycloheptanones and bicycloalkanonecarbonitriles in good yield and with high selectivity, in a single synthetic operation.

Quaternary oxonitriles are stereoselectively generated from the union of five-, six-, and seven-membered 2-chloroalkenecarbonitriles with chiral alcohols via a Claisen rearrangement. The strategy rests on a new conjugate addition-elimination of allylic alkoxides to 2-chlorocycloalkenecarbonitriles to afford substituted 2-alkoxyalkenenitriles. Subsequent thermolysis unmasks a cyclic oxonitrile while selectively forming a new quaternary center with enantiomeric ratios typically greater than 9:1. The overall alkylation strategy addresses the challenge of enantioselectively generating hindered, quaternary centers while simultaneously installing ketone, nitrile, and olefin functionalities.

In order to construct a quaternary center in the product, cycloheptene (I) and bridged analogues of type (VI) and (IX) are used as substrates in the addition of different allylic alcohols and propargylic alcohol (VII).

Objective: This study aimed to evaluate the outcomes of maximal levator resection in cases of congenital myogenic ptosis with poor levator function. Method: Thirty-threeptotic eyelids of 30 cases undergoing maximal levator resection were retrospectively included. There were 18 male and 12 female cases. The mean age of the cases was 12.55±5.3 years (range, 4-26 years). For all eyes, vertical palpebral aperture, margin reflex distance, levator functions, and upper eyelid crease height were measured. Ptosisseverity was "mild" when the eyelid elevation was ≤2 mm; "moderate" when the eyelid elevation was 3 mm; and "severe" when the eyelid elevation was ≥4 mm. The mean age of the cases (18 males and 12 females) was 12.55±5.3 years (range, 4-26 years). Results and Conclusion: The mean ptosis severity (vertical palpebral aperture) was 5.136 mm preoperatively and 0.818 mm at the postoperative Month 3 (p<0.001). Surgical outcomes were successful in 26 eyes (78%), satisfactory in 4 eyes (12%), and unsuccessful in 3 eyes (9%).Conclusively, successful outcomes were obtained after maximal levator resection in ptosis cases with poor levator functionin most of casses.