Alkylation of l- and d-menthyl pentanoate with (20S)-20-iodomethyl-4 alpha-methyl-5 alpha-pregnane

Demir, Ayhan Sıtkı
The alkylation of l- and d-menthyl valerate with n-hexyl iodide and with (20S)-20-iodomethyl-4 alpha-methyl-5 alpha-pregnane gave modest levels of diastereoselection. The chirality of the ester group favoured slight degree of selectivity. The chiral centers had limited impact on diastereoselectivity.


Transition structures, energetics, and nucleus-independent chemical shifts for 6 pi electrocyclizations of dienylketenes to cyclohexadienones: A DFT study
Zora, Metin (American Chemical Society (ACS), 2004-03-19)
6pi electrocyclizations of dienylketenes to 2,4-cyclohexadienones have been investigated at the (U)B3LYP/6-31G* level and found to be a favored and exothermic process for most dienylketenes. As evidenced by calculations, dienylketene cyclizations proceed via a pseudopericyclic process. If the terminal double bond of dienylketenes is embedded into a benzenoid-type aryl moiety, the partial or complete loss of aromaticity, as indicated by NICS values, increases the activation barrier and makes the reaction les...
AKHMEDOV, IM; Tanyeli, Cihangir; AKHMEDOV, MA; MOHAMMADI, M; DEMIR, AS (Informa UK Limited, 1994-01-01)
The asymmetric ene reactions of prochiral chloroaldehydes, chloral and 2,3-dichlorobutanal with 2-methylpropanal in the presence of BF3 l-menthylethyl etherate gave optically active homoallylic alcohols in 16-22% ee. The dechlorination of the chloro alcohols lead to the unsaturated derivatives of alcohols.
Chemoenzymatic synthesis of enantiomerically enriched 2-oxobicyclo[m.1.0]alkan-3-yl acetate derivatives
Atlı, Selin; Tanyeli, Cihangir; Department of Chemistry (2005)
a,β-Unsaturated cyclic ketones were selectively oxidized on a'- positions using Mn(OAc)3 and Pb(OAc)4, respectively. The resultant racemic a'-acetoxylated substrates were resolved into corresponding enantiomerically enriched a'-hydroxylated and a'-acetoxylated compounds via PLE hydrolysis. a'-Hydroxylated compounds are racemized quickly, so they were acetylated with acetyl chloride and pyridine in situ to give the corresponding a'-acetoxylated compounds. Resultant a'-acetoxy a,β-unsaturated cyclic ketones r...
Uncatalyzed addition of TMSCN to acylphosphonates
Demir, Ayhan Sıtkı; Reis, Omer; Kayalar, Metin; Eymur, Serkan; Reis, Barbaros (Georg Thieme Verlag KG, 2006-12-01)
The cyanosilylations of various alkyl- and arylphosphonates under comparatively mild conditions furnished the trimethyl-silyloxycyanophosphonates in high yield. The addition to ketophosphonate functions works without the influence of a catalyst.
Unusual manganese(III)-mediated oxidative free radical additions of 1,3-dicarbonyl compounds to benzonorbornadiene and 7-heterobenzonorbornadienes: Mechanistic studies
Caliskan, Rasit; Ali, Mohamed Fadelalla; Sahin, Ertan; Watson, William H.; Balcı, Metin (American Chemical Society (ACS), 2007-04-27)
Benzonorbornadiene and heterobenzonorbornadiene were reacted with dimedone/acetylacetone and Mn(OAc)3 in the presence and absence of Cu(OAc)2. The reaction of benzonorbornadiene with dimedone gave mainly the dihydrofuran addition product, whereas the reaction with acetylacetone produced a rearranged product in addition to the dihydrofuran derivative. On the other hand, oxanorbornadiene gave unusual products such as the cycloproponated compound and a product arising from the incorporation of 2 mol of dimedon...
Citation Formats
A. S. Demir, “Alkylation of l- and d-menthyl pentanoate with (20S)-20-iodomethyl-4 alpha-methyl-5 alpha-pregnane,” SYNTHETIC COMMUNICATIONS, pp. 4519–4530, 1996, Accessed: 00, 2020. [Online]. Available: