25.03.2013 Views

Narcissus and Daffodil

Narcissus and Daffodil

Narcissus and Daffodil

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

316 V.N. Bulavka <strong>and</strong> O.N. Tolkachev<br />

MeO<br />

O<br />

PhCH2O<br />

67<br />

MeO OCH2Ph<br />

68 69 70<br />

71<br />

R=H R=COCF3<br />

MeO<br />

O<br />

F3C<br />

H2NCO<br />

MeN<br />

NH2<br />

O<br />

N<br />

OH<br />

CHO<br />

O<br />

O<br />

O<br />

MeO<br />

O<br />

O<br />

MeO<br />

O<br />

O<br />

OMe<br />

O<br />

N<br />

OMe<br />

HN<br />

OMe<br />

72<br />

OH<br />

F3C<br />

73<br />

OPO(OEt)2<br />

OPO(OEt)2<br />

74<br />

OR<br />

HO<br />

MeOCO<br />

NR<br />

PhCH2O OMe<br />

O<br />

NC<br />

OMe<br />

MeN<br />

OPO(OEt)2<br />

O<br />

OCH2Ph<br />

Me<br />

O<br />

final protection group elimination with Na-liquid NH 3 gave the expected compound<br />

(+)-1 in 72% yield (0.63% total yield).<br />

Despite the low total yield of galanthamine, this work was of a great importance<br />

because of its prospects for further improvement. Thus, the tyrosine hydroxyl<br />

group was not protected, <strong>and</strong> this shows that the protection <strong>and</strong> de-protection of<br />

O<br />

OMe<br />

OPO(OEt)2<br />

MeN<br />

75 76 77 78<br />

R=H R=COCH3<br />

HO<br />

MeOCO<br />

N<br />

COCF3<br />

HO OMe<br />

OH<br />

OH<br />

OH<br />

O<br />

OMe<br />

OPO(OEt)2<br />

Figure 12.10 Synthesis of enantiomeric galanthamine (1) (Shimizu et al., 1977, 1978).<br />

(+)-1

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!