Cobalt(0)-mediated addition of α-haloesters and α-haloketones to (R)-2,3-O-cyclohexylideneglyceraldehyde

Tetrahedron Asymmetry

Volumn 8, Issue 24, 1997, Pages 4011-4019

  Orsini, Fulvia ^a   Leccioli, Cristina ^a  

^a Dipartimento di Chimica Organica e Industriale   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

CYCLOHEXANE DERIVATIVE; GAMMA BUTYROLACTONE DERIVATIVE; KETONE DERIVATIVE; VALERIC ACID DERIVATIVE;

ARTICLE; CHIRALITY; COMPLEX FORMATION; DRUG PURIFICATION; DRUG SYNTHESIS; IN VITRO STUDY; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; PRIORITY JOURNAL; REACTION ANALYSIS; STEREOCHEMISTRY;

EID: 0031584592     PISSN: 09574166     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0957-4166(97)00521-1     Document Type: Article

References (14)

1. Orsini, F.; Pelizzoni, F.; Pulici, M.; Vallarino, L. M. J. Org. Chem. 1994, 59, 1-4.
2. Orsini, F.; Pulici, M.; Vallarino, L. M. J. Organomet. Chem. 1995,495, 1-5.
3. Orsini, F.; Pulici, M. 'Highlights on recent advancements in Reformatsky-type reactions: the Cobalt Approach' in Trends in Organometallic Chemistry (Book), J. Menon, Ed., Research Trends Pub., New Delhi, 1994, l. 625-667.
4. Orsini, F. J. Org. Chem. 1997, 62, 1159-1163.
5. Trimethyl phosphine should be, however, preferred with reaction products unstable with respect to chromatography. Cobalt derivatives present in the organic phase can be separated by washing with a saturated EDTA sodium salt solution.
6. To investigate whether an organomagnesium compound might be involved, parallel experiments were performed adding the α-halo compound and (R)-2,3-O-cyclohexylideneglyceraldehyde to magnesium alone in tetrahydrofuran. The amount of halo compound, aldehyde and magnesium were the same in both series of experiments and so were the other experimental conditions (temperature, time of reaction, speed of stirring). The reactions in the absence of cobalt were generally slower, less reproducible and required a variable period of induction. Once started the reaction afforded a mixture of products.
7. House, H. O.; Crumrine, D. S.; Teranishi, A. Y.; Olmstead, H. D. J. Am. Chem. Soc. 1973, 95, 3310-3324.
8. Heathcock, C. H.; Pirrung, M. C; Sohn, J. E. J. Org. Chem. 1979, 44, 4294-4299.
9. Chattopadhyay, A.; Mamdapur, V. R. J. Org. Chem. 1995, 585-587.
10. Definitive and unequivocal stereochemical assignment, with particular reference to the 3,4-positions will, however, come from correlation to known compounds.
11. A tentative explanation could be the presence in solution of magnesium salts which may favour the β-chelation model with respect to β-chelation model and therefore reinforce the anti-selectivity according to the Felkin-Anh model. Magnesium bromide, however, was not effective in this respect in the addition of furyllithium to protected glyceraldehyde (Mukaiyama, T.; Suzuki, K; Yamada, T; Tabusa, F. Tetrahedron 1990, 46, 265-276).
12. In this particular case the classical Reformatsky reaction between tert-butyl α-bromoacetate and benzaldehyde did not proceed satisfactorily at room temperature.
13. 2O of the lactone ring.
14. 3 are very similar (3.5 Hz and 3.0 Hz respectively). Other diastereoisomers were detected in traces in the NMR spectrum.