3-Acetoxy-7-methyl-2,3-dihydro

It was shown earlier that 2-methoxy-5,6-dihydro-2H-pyrans (279, R = Me R = H, COzBu) readily added methanol across the double bond, forming mixtures of stereoisomeric 2,4-dimethoxytetrahydropyrans. This addition reaction was extended to acetic acid, which was added in the presence of sulfuric acid to 6-acetoxy-methyl-2-methoxy-5,6-dihydro-2H-pyran (326,R-... 

Selective catalytic hydrogenation of the 6,7-double bond of 17/3-acetoxy-7-methylandrosta-4,6-dien-3-one was achieved with Pd-C-PhCH20H and gave the 7/8-methyl dihydro-compound. Added FeCls has been reported to improve the selectivity of reduction of a,/S-enones in metal-ammonia reactions, thereby improving the yield of the saturated ketones. Similar improvements were observed in the lithium-ethylamine reductions at -78 C when a substantial excess of lithium was used and t-butyl alcohol was the proton source. The influence of solvent and added nitrogenous bases on the stereoselectivity of hydrogenation of A - and A -3-oxo-steroids with Pd catalysts has been studied, and the stereoselectivity of Pd-catalysed hydrogenation of various A -7-oxo-steroids has been reported to be unaffected by substituents at C-3 or C-17. 

Acetoxymethyl-ds,trans,cis,trans-cyclonona-l,3,5,7-tetraene, prepared from lithium cyclononatetraenide and bromomethyl acetate at — 30 °C, was converted into 9-methylene-ci5,trans,cis,trans-cyclonona-l,3,5,7-tetraene by KOBuS Both 9-acetoxy-methyl- and 9-methylene-cyclononatetraenides were converted into the dihydro-indenes (222 R = CH2 H, CH2OAC) on warming. ... 

Benzo[6]furan, trans-3-acetoxy-2,3-dihydro-2-methyl-... 

Acetoxy-7-chloro-1 -methyl-5-phenyl-l, 3-dihydro-2H-1,4-benzodiazepin-2-one Sodium hydroxide... 

According to British Patent 1,022,645 3.4 g of 3-acetoxy-7-chloro-1-methyl-5-phenyl-1,3-dihy-dro-2H-1,4-benzodiazepin-2-one suspended in 80 ml alcohol was treated with 6 ml of 4 N NaOH. After Complete solution had taken place, a solid precipitated this solid was redissolyed by the addition of 80 ml of water. The solution was acidified with acetic acid to give white crystals which were recrystallized from alcohol to yield 7-chloro-3-hydroxy-5-phenyl-1-methvl-1,3-dihydro-2H-1,4-benzodiazepin-2-one, MP 119° to 121°C. 

C14H11CI2NS 53885-64-6) see Ticlopidine A-[(2-chlorophenyl)methyl]-2-thiopheneethanamine (C13H14CINS 69067-/7-2) sec Ticlopidine 7-chloro-5-phenyl-2-oxo-3-acetoxy-l,3-dihydro-2//-l,4-benzodiazepine... 

Hydroxy-6-methyl-5,6-dihydropyran-2-one (597) is brominated by NBS at C-3 (78JHC1153). More than one product is often obtained in this type of reaction, for example from 2,3-dihydro-4//-pyran (593), but in acetic acid this reaction gives 2-acetoxy-3-bromotetrahydropyran (599) (58JOC1128). 2,3-Dihydro-4H-pyran reacts normally with hydroboration reagents to give tetrahydropyran-3-ol in 80% yield (70JOC2282). 

Benzo[6]furan, (rans-3-acetoxy-2,3-dihydro-2-methyl-5,7-dinitro- H NMR, 4, 571 (71JOC1805)... 

Treatment of 3-Acetoxy-5-acetoxymethyl-2-methyl-4-pyridinecarbonitrile (18) with ethyl magnesium bromide is reported to give 3-ethyl-8-hydroxy-3,7-dimethyI-3,4-dihydro-2,6-naphthyridin-1 (2//)-one (19) (20%, after separation from another product).240... 

Like the foregoing isomeric substrates (Section 2.2.7), these isoxazolopyrazines were frequently made from pyrazines. Thus 3-(/V-hydroxyamidino)-2(l//)-pyrazi-none (102) was converted in two stages into isoxazolo[4,5-b]pyrazin-3-aminc (103), which on vigorous treatment with acetic anhydride afforded 2-acetoxy-3-(5-methyl-l,2,4-oxadiazol-3-yl)pyrazine (104) in 78% yield the same substrate (103) in hot formic acid for 5 min gave mainly 3-(l,2,4-oxadiazol-3-yl)-2(l/7)-pyrazi-none (105) (50%) but if heating was prolonged for 3 h only 3-oxo-3,4-dihydro-2-pyrazinecarbonitrile (106) was obtained, presumably via the oxadiazolopyrazine (105).1115... 

Ethan 2-Acetamino-2-hydroxy-l-oxo-1-phenyl- E14a/2, 68 (R-CHO/R-CO-NH2), 215 (R-CHO/Amin) Furo 2,3-b[pyridin 3-Acetoxy-3-methyl-2,3-dihydro- E6b/1, 117 (OH -+ O-CO-CH3) Hydroxylamln N-[4-(rra s-2-Methoxycarbonyl-ethenyl)-phenyl]- E16a, 58 (Nitro-Red.) Malonsanre Methyl- -anilid E5. 

Furan 2-Acetoxy-2-(diacetoxy-methyl)-5-nitro-2,5-dihydro-IV/la, 781... 

Acetoxy-l -methyl-2-oxo-l,2-dihydro- VII/3b, 546 1 -(Carboxy-methyl)-2-methoxy- X/4, 641... 

The nitroso nitro compounds prepared from indene91 and various methyl- or ethyl-substituted indenes by reaction with dinitrogen trioxide92 (32-43% yield) were converted to 1-acetoxy-2,3-dihydro-2-nitro-l/f-indenes with undetermined configuration. 

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